U.S. patent number 10,209,803 [Application Number 15/163,210] was granted by the patent office on 2019-02-19 for touch sensor and liquid crystal display including the same.
This patent grant is currently assigned to Samsung Display Co., Ltd.. The grantee listed for this patent is Samsung Display Co., Ltd.. Invention is credited to Joon Chul Goh, Sang Mi Kim, Kyoung Ho Lim.
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United States Patent |
10,209,803 |
Kim , et al. |
February 19, 2019 |
Touch sensor and liquid crystal display including the same
Abstract
There are provided a touch sensor and a liquid crystal display
including the same. A touch sensor includes a plurality of driving
electrodes, a plurality of sensing electrodes intersecting the
driving electrodes, a plurality of piezoelectric materials disposed
between the driving electrodes and the sensing electrodes at
intersection points of the driving electrodes and the sensing
electrodes, and a touch controller for detecting a touch position
and a touch pressure by using sensing signals output from the
sensing electrodes.
Inventors: |
Kim; Sang Mi (Yongin-si,
KR), Goh; Joon Chul (Yongin-si, KR), Lim;
Kyoung Ho (Yongin-si, KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
Samsung Display Co., Ltd. |
Yongin-si, Gyeonggi-do |
N/A |
KR |
|
|
Assignee: |
Samsung Display Co., Ltd.
(KR)
|
Family
ID: |
58523878 |
Appl.
No.: |
15/163,210 |
Filed: |
May 24, 2016 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20170108973 A1 |
Apr 20, 2017 |
|
Foreign Application Priority Data
|
|
|
|
|
Oct 20, 2015 [KR] |
|
|
10-2015-0146036 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F
3/044 (20130101); G02F 1/134309 (20130101); G06F
3/0443 (20190501); G02F 1/13338 (20130101); G06F
3/0414 (20130101); G02F 1/133512 (20130101); G02F
1/13394 (20130101); G06F 3/0412 (20130101); G06F
3/0416 (20130101); G02F 1/133514 (20130101); G06F
3/0446 (20190501); G06F 2203/04105 (20130101); G02F
2001/133394 (20130101) |
Current International
Class: |
G06F
3/041 (20060101); G02F 1/1343 (20060101); G02F
1/1339 (20060101); G02F 1/1335 (20060101); G02F
1/1333 (20060101); G06F 3/044 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
10-2014-0078456 |
|
Jun 2014 |
|
KR |
|
10-1439718 |
|
Sep 2014 |
|
KR |
|
10-1482022 |
|
Jan 2015 |
|
KR |
|
10-2015-0023890 |
|
Mar 2015 |
|
KR |
|
Primary Examiner: Awad; Amr
Assistant Examiner: Matthews; Andre
Attorney, Agent or Firm: Innovation Counsel LLP
Claims
What is claimed is:
1. A touch sensor comprising: a plurality of driving electrodes; a
plurality of sensing electrodes intersecting the driving
electrodes; a plurality of discrete piezoelectric materials
disposed between the driving electrodes and the sensing electrodes
at intersection points of the driving electrodes and the sensing
electrodes; and a touch controller configured to detect a touch
position and a touch pressure by using sensing signals output from
the sensing electrodes, wherein the touch controller includes: a
touch position detector configured to detect the touch position by
using alternating current (AC) components of the sensing signals, a
touch pressure detector configured to detect the touch pressure by
using direct current (DC) components of the sensing signals, and a
plurality of AC bypass capacitors disposed between the sensing
electrodes and the touch position detector, the plurality of AC
bypass capacitors selectively transmitting the AC components of the
sensing signals to the touch position detector.
2. The touch sensor of claim 1, wherein the touch pressure detector
includes: an analog-digital converter (ADC) receiving the DC
components of the sensing signal and configured to convert the DC
components of the sensing signals into digital data; and a
converting unit connected to the ADC and configured to convert the
digital data output from the ADC into touch pressure
information.
3. The touch sensor of claim 2, wherein the plurality of discrete
piezoelectric materials are disposed on a plurality of column
spacers, respectively.
4. The touch sensor of claim 3, wherein the plurality of discrete
piezoelectric materials and the plurality of column spacers are
completely overlap in a plan view.
5. The touch sensor of claim 1, wherein the touch pressure detector
includes: an analog-digital converter (ADC) receiving the DC
components of the sensing signal and configured to convert the DC
components of the sensing signals into digital data; and a
converting unit connected to the ADC and configured to convert the
digital data output from the ADC into touch pressure
information.
6. The touch sensor of claim 1, wherein the touch controller
further includes a driving signal supply unit configured to supply
driving signals to the driving electrodes.
7. The touch sensor of claim 1, wherein the plurality of discrete
piezoelectric materials are disposed on a plurality of column
spacers, respectively.
8. The touch sensor of claim 4, wherein the plurality of discrete
piezoelectric materials and the plurality of column spacers are
completely overlap in a plan view.
9. A liquid crystal display, comprising: a first substrate and a
second substrate opposite to each other; a plurality of driving
electrodes formed on the first substrate; a black matrix formed
under the second substrate; a plurality of column spacers disposed
under the black matrix, the plurality of column spacers extending
toward the first substrate; a plurality of sensing electrodes
formed over the column spacers and the black matrix, the plurality
of sensing electrodes intersecting the driving electrodes;
plurality of discrete piezoelectric materials disposed between the
driving electrodes and the sensing electrodes at intersection
points of the driving electrodes and the sensing electrodes; and a
touch controller configured to detect a touch position and a touch
pressure by using sensing signals output from the sensing
electrodes, wherein the touch controller includes: a touch position
detector configured to detect the touch position by using AC
components of the sensing signals; and a touch pressure detector
configured to detect the touch pressure by using DC components of
the sensing signals, and a plurality of AC bypass capacitors
disposed between the sensing electrodes and the touch position
detector, the plurality of AC bypass capacitors selectively
transmitting the AC components of the sensing signals to the touch
position detector.
10. The liquid crystal display of claim 9, wherein the plurality of
driving electrodes overlap the black matrix.
11. The liquid crystal display of claim 9, further comprising a
liquid crystal layer disposed between the first substrate and the
second substrate.
12. The liquid crystal display of claim 9, wherein the touch
pressure detector includes: an ADC receiving the DC components of
the sensing signal and configured to convert the DC components of
the sensing signals into digital data; and a converting unit
connected to the ADC and configured to convert the digital data
output from the ADC into touch pressure information.
13. The liquid crystal display of claim 9, wherein the touch
controller further includes a driving signal supply unit configured
to supply driving signals to the driving electrodes.
14. The liquid crystal display of claim 9, wherein the plurality of
discrete piezoelectric materials are disposed on the plurality of
column spacers, respectively.
15. The liquid crystal display of claim 14, wherein the plurality
of discrete piezoelectric materials completely overlaps with the
plurality of column spacers in a plan view.
Description
RELATED APPLICATIONS
This application claims priority to and the benefit of Korean
Patent Application No. 10-2015-0146036, filed on Oct. 20, 2015, in
the Korean Intellectual Property Office, the entire contents of
which are incorporated herein by reference in their entirety.
BACKGROUND
1. Field
An aspect of the present disclosure relates to a touch sensor and a
liquid crystal display including the same.
2. Description of the Related Art
As interest in information displays and demand for portable
information media increases, research and commercialization on
display devices replacing cathode ray tubes (CRTs) that are
existing display devices have recently been actively conducted.
In particular, a liquid crystal display (LCD) is a device that
displays an image using optical anisotropy of liquid crystals, and
is widely being applied to TVs, notebook computers, monitors,
tablet computers, cellular phones, and the like because the LCD has
an excellent resolution, color rendering capability, picture
quality, and the like.
Recently, a touch sensor capable of sensing a user's touch has been
embedded in the LCD, so that the user can more conveniently use the
LCD.
Accordingly, a conventional touch sensor merely performed a
function of detecting a touch position, and does not detect a
user's touch pressure. In addition, a separate pressure sensor
should be installed in the touch sensor so as to detect a touch
pressure.
SUMMARY
Embodiments provide a touch sensor and a liquid crystal display
including the same, which can detect not only a user's touch
position but also a touch pressure.
Technical objects to be achieved in the present disclosure are not
limited to those described above, and other technical objects not
described herein will be apparently understood by those skilled in
the art from the disclosure of the present disclosure.
According to an aspect of the present disclosure, there is provided
a touch sensor including: a plurality of driving electrodes; a
plurality of sensing electrodes disposed to intersect the driving
electrodes; a plurality of piezoelectric materials disposed between
the driving electrodes and the sensing electrodes at intersection
points of the driving electrodes and the sensing electrodes; and a
touch controller configured to detect a touch position and a touch
pressure by using sensing signals output from the sensing
electrodes.
The touch controller may include a touch position detector
configured to detect the touch position by using alternating
current (AC) components of the sensing signals; and a touch
pressure detector configured to detect the touch pressure by using
direct current (DC) components of the sensing signals.
The touch controller may further include a plurality of AC bypass
capacitors disposed between the sensing electrodes and the touch
position detector, the plurality of AC bypass capacitors
selectively transmitting the AC components of the sensing signals
to the touch position detector.
The touch pressure detector may include an analog-digital converter
(ADC) receiving the DC components of the sensing signal and
configured to convert the DC components of the sensing signals into
digital data; and a converting unit connected to the ADC and
configured to convert the digital data output from the ADC into
touch pressure information.
The plurality of piezoelectric materials may be disposed on the
plurality of column spacers, respectively.
The plurality of piezoelectric materials and the plurality of
column spacers may be completely overlap in a plan view.
The touch controller may further include a driving signal supply
unit configured to supply driving signals to the driving
electrodes.
According to an aspect of the present disclosure, there is provided
a liquid crystal display, including: a first substrate and a second
substrate opposite to each other; a plurality of driving electrodes
formed on the first substrate; a black matrix formed under the
second substrate; a plurality of column spacers disposed under the
black matrix, the plurality of column spacers extending toward the
first substrate; a plurality of sensing electrodes formed over the
column spacers and the black matrix, the plurality of sensing
electrodes intersecting the driving electrodes; a plurality of
piezoelectric materials respectively disposed between the driving
electrodes and the sensing electrodes at intersection points of the
driving electrodes and the sensing electrodes; and a touch
controller configured to detect a touch position and a touch
pressure by using sensing signals output from the sensing
electrodes.
The plurality of driving electrodes may overlap the black
matrix.
The liquid crystal display may further include a liquid crystal
layer disposed between the first substrate and the second
substrate.
The touch controller may include a touch position detector
configured to detect the touch position by using AC components of
the sensing signals; and a touch pressure detector configured to
detect the touch pressure by using DC components of the sensing
signals.
The touch controller may further include a plurality of AC bypass
capacitors disposed between the sensing electrodes and the touch
position detector, the plurality of AC bypass capacitors
selectively transmitting the AC components of the sensing signals
to the touch position detector.
The touch pressure detector may include an ADC receiving the DC
components of the sensing signal and configured to convert the DC
components of the sensing signals into digital data; and a
converting unit connected to the ADC and configured to convert the
digital data output from the ADC into touch pressure
information.
The touch controller may further include a driving signal supply
unit configured to supply driving signals to the driving
electrodes.
As described above, according to the present disclosure, it is
possible to provide a touch sensor and a liquid crystal display
including the same, which can detect not only a user's touch
position but also a touch pressure.
Also, according to the present disclosure, it is possible to
provide a liquid crystal display capable of detecting a touch
pressure by using the existing column spacers.
The effects of the present disclosure are not limited to the
effects described above, and the other effects not stated in the
above will be clearly understood by those skilled in the art from
the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Example embodiments will now be described more fully hereinafter
with reference to the accompanying drawings; however, they may be
embodied in different forms and should not be construed as limited
to the embodiments set forth herein. Rather, these embodiments are
provided so that this disclosure will be thorough and complete, and
will fully convey the scope of the example embodiments to those
skilled in the art.
In the drawing figures, dimensions may be exaggerated for clarity
of illustration. It will be understood that when an element is
referred to as being "between" two elements, it can be the only
element between the two elements, or one or more intervening
elements may also be present. Like reference numerals refer to like
elements throughout.
FIG. 1 is a diagram showing a touch sensor according to an
embodiment of the present disclosure.
FIG. 2 is a diagram showing a section of the touch sensor shown in
FIG. 1.
FIG. 3 is a diagram showing a touch controller according to an
embodiment of the present disclosure.
FIGS. 4A and 4B are waveform diagrams showing a sensing signal
according to an embodiment of the present disclosure.
FIG. 5 is a diagram showing a touch pressure detector according to
an embodiment of the present disclosure.
FIG. 6 is a diagram showing a liquid crystal display according to
an embodiment of the present disclosure.
FIGS. 7 and 8 are diagrams showing sections of the liquid crystal
display shown in FIG. 6.
DETAILED DESCRIPTION
Hereinafter, exemplary embodiments of the present disclosure will
be described in detail with reference to the accompanying drawings.
However, the present disclosure is not limited to the embodiments
but may be implemented into different forms. These embodiments are
provided only for illustrative purposes and for full understanding
of the scope of the present disclosure by those skilled in the art.
Like reference numerals indicate like elements throughout the
specification and drawings.
Hereinafter, a touch sensor and a liquid crystal display device
including the same according to embodiments of the present
disclosure will be described with reference to the accompanying
drawings.
FIG. 1 is a diagram showing a touch sensor according to an
embodiment of the present disclosure. FIG. 2 is a diagram showing a
section of the touch sensor shown in FIG. 1. Particularly, a
section of the touch sensor 100, taken along line A-A' of FIG. 1,
is illustrated in FIG. 2.
Referring to FIGS. 1 and 2, the touch sensor 100 according to the
embodiment of the present disclosure may include driving electrodes
110, sensing electrodes 120, piezoelectric materials 210, and a
touch controller 150.
The driving electrodes 110 and the sensing electrodes 120 may be
arranged to intersect each other.
The driving electrode 110 is formed along a first direction (e.g.,
an X-axis direction) and may be arranged in plurality along a
second direction (e.g., a Y-axis direction) intersecting the first
direction.
Also, the driving electrodes 110 may receive driving signals Ds
from the touch controller 150.
For example, the driving electrodes 110 may include first to fourth
driving electrodes Tx1 to Tx4. That is, a case where four driving
electrodes Tx1 to Tx4 exist is illustrated in FIG. 1.
However, the number of the driving electrodes 110 is not limited
thereto and may be variously changed.
The sensing electrodes 120 are arranged to be spaced apart from the
driving electrodes 110, so that the driving electrodes 110 and the
sensing electrodes 120 can be operated as a capacitive type touch
sensor which uses a capacitance coupling to sense a touch
event.
The sensing electrode 120 is formed along the second direction
(e.g., the Y-axis direction) and may be arranged in plurality along
the first direction (e.g., the X-axis direction).
The sensing electrodes 120 may output sensing signals Vs1 to Vs4 to
the touch controller 150.
For example, the sensing electrodes 120 may include first to fourth
sensing electrodes Rx1 to Rx4. That is, a case where four sensing
electrodes Rx1 to Rx4 exist is illustrated in FIG. 1.
However, the number of the sensing electrodes 120 is not limited
thereto and may be variously changed.
In FIG. 1, it is illustrated that the driving and sensing
electrodes 110 and 120 are formed in a bar shape, the shape of the
driving and sensing electrodes 110 and 120 may be variously
changed.
In FIGS. 1 and 2, it is illustrated that the driving electrodes 110
are disposed under the sensing electrodes 120. However, it will be
apparent that the driving electrodes 110 may be disposed over the
sensing electrodes 120.
According to the above-described arrangement of the driving and
sensing electrodes 110 and 120, mutual capacitances between the
driving electrodes 110 and the sensing electrodes 120 are formed at
points at which the driving electrodes 110 and the sensing
electrodes 120 intersect each other, and intersection points Rc at
which the mutual capacitances are formed may serve as sensing cells
for implementing touch recognition, respectively.
Referring to FIGS. 1 and 2, the piezoelectric materials 210 may be
disposed between the driving electrodes 110 and the sensing
electrodes 120 at the intersection points Rc of the driving
electrodes 110 and the sensing electrodes 120, respectively.
In this case, the piezoelectric materials 210 may be contacted with
the driving electrodes 110 and the sensing electrodes 120,
respectively. The piezoelectric materials 210 may be directly
contacted with the driving electrodes 110 and the sensing
electrodes 120, respectively.
The piezoelectric materials 210 are materials for generating a
predetermined voltage corresponding to a pressure applied thereto
and may be patterned in a specific form through a photolithography
process or the like.
The touch controller 150 may detect a touch position and a touch
pressure by using the sensing signals Vs1 to Vs4 output from the
sensing electrodes 120.
For example, the touch controller 150 may detect a touch position
by using alternating current (AC) components of the sensing signals
Vs1 to Vs4, and detect a touch pressure by using direct current
(DC) components of the sensing signals Vs1 to Vs4.
FIG. 3 is a diagram showing a touch controller according to an
embodiment of the present disclosure.
Referring to FIG. 3, the touch controller 150 according to the
embodiment of the present disclosure may include a touch position
detector 310, a touch pressure detector 320, a driving signal
supply unit 350, and AC bypass capacitors Cb1 to Cb4.
The touch position detector 310 may detect a touch position by
using AC components Ac1 to Ac4 of the sensing signals Vs1 to Vs4
output from the sensing electrodes 120.
For example, when a user's touch is generated at a specific
position, the mutual capacitance of an intersection point Rc
adjacent to the specific position is changed. As a result, the AC
component of the sensing signal output from the sensing electrode
120 related to the intersection point Rc is changed.
Thus, the touch position detector 310 can detect a touch position
through amounts of changes in the AC components Ac1 to Ac4.
The touch pressure detector 320 may detect a touch pressure by
using DC components Dc1 to Dc4 of the sensing signals Vs1 to Vs4
output from the sensing electrodes 120.
For example, when a user's touch is generated at a specific
position, the piezoelectric material 210 at an intersection point
Rc adjacent to the specific position is pressed to generate a
predetermined voltage. Hence, the DC component of the sensing
signal output from the sensing electrode 120 related to the
intersection point Rc is changed.
Thus, the touch pressure detector 320 can detect a touch pressure
through amount of changes in the DC components Dc1 to Dc4.
The AC bypass capacitors Cb1 to Cb4 are disposed between the
sensing electrodes 120 and the touch position detector 310, and may
transmit the AC components Ac1 to Ac4 of the sensing signals Vs1 to
Vs4 to the touch position detector 310.
For example, a first bypass capacitor Cb1 may bypass an AC
component Ac1 of a first sensing signal Vs1, a second bypass
capacitor Cb2 may bypass an AC component Ac2 of a second sensing
signal Vs2, a third bypass capacitor Cb3 may bypass an AC component
Ac3 of a third sensing signal Vs3, and a fourth bypass capacitor
Cb4 may bypass an AC component Ac4 of a fourth sensing signal
Vs4.
In this case, DC components Dc1 to Dc4 of the sensing signals Vs1
to Vs4, which are not bypassed by the AC bypass capacitors Cb1 to
Cb4, may be input to the touch pressure detector 320.
The driving signal supply unit 350 may supply driving signals Ds to
the driving electrodes 110.
For example, the driving signal supply unit 350 may sequentially
supply the driving signals Ds to the driving electrodes 110.
When the touch sensor 100 is employed in a display device, the
driving signal supply unit 350 may supply the driving signals Ds
during a touch driving period, and stop the supply of the driving
signals Ds during an image display period.
FIGS. 4A and 4B are waveform diagrams showing a sensing signal
according to an embodiment of the present disclosure. In FIGS. 4A
and 4B, the first sensing signal Vs1 output from the first sensing
electrode Rx1 is representatively illustrated, and the AC and DC
components Ac1 and Dc1 of the first sensing signal Vs1 are also
illustrated.
When assuming that a touch is generated at an intersection portion
Rct of the fourth driving electrode Tx4 and the first sensing
electrode Rx1 in FIG. 1, an operation of the touch sensor 100 will
be described.
While the driving signal Ds is being sequentially supplied to the
first driving electrode Tx1, the second driving electrode Tx2, and
the third driving electrode Tx3, the first sensing signal Vs1 has a
waveform shown in FIG. 4A due to influence of the driving signal
Ds.
While the driving signal Ds is being supplied to the fourth driving
electrode Tx4, mutual capacitance at the intersection point Rct is
decreased by a user's touch, and simultaneously, a pressure is
applied to the piezoelectric material 210 disposed at the
intersection point Rct. Therefore, the first sensing signal Vs1 is
changed as shown in FIG. 4B.
That is, as the mutual capacitance is decreased, the amplitude of
the AC component Ac1 of the first sensing signal Vs1 is decreased,
and the value of the DC component Dc1 of the first sensing signal
Vs1 is increased by a voltage generated from the piezoelectric
material 210.
Thus, the touch position detector 310 recognizes an amount of the
change in the AC component Ac1 of the first sensing signal Vs1, to
detect that the touch has generated at the specific intersection
point Rct.
Also, the touch pressure detector 320 recognizes an amount (DC
offset) of the change in the DC component Dc1 of the first sensing
signal Vs1, to detect a pressure applied to the specific
intersection point Rct.
That is, as the magnitude of a touch pressure increases, the amount
(DC offset) of the change in the DC component Dc1 increases. Thus,
the touch pressure detector 320 can estimate the magnitude of the
touch pressure from the amount of the change (DC offset) in the DC
component Dc1.
Meanwhile, any touch is not generated at the intersection points Rc
related to the second sensing electrode Rx2, the third sensing
electrode Rx3, and the fourth sensing electrode Rx4, and therefore,
the second sensing signal Vs2, the third sensing signal Vs3, and
the fourth sensing signal Vs4 all have the waveform shown in FIG.
4A.
Information on the touch position detected by the touch position
detector 310 and information on the touch pressure detected by the
touch pressure detector 320 may be transmitted to a timing
controller (T-CON) or an application processor (AP).
FIG. 5 is a diagram showing a touch pressure detector according to
an embodiment of the present disclosure.
Referring to FIG. 5, the touch pressure detector 320 according to
the embodiment of the present disclosure may include an
analog-digital converter (ADC) 510, a converting unit 520, and a
memory 550.
The ADC 510 may receive DC components Dc1 to Dc4 of sensing signals
Vs1 to Vs4, and convert the DC components Dc1 to Dc4 into digital
data G1 to G4.
Since values of the DC components Dc1 to Dc4 are changed depending
on the magnitude of a touch pressure, the digital data G1 to G4 may
also be changed depending on the magnitude of the touch
pressure.
The converting unit 520 may receive digital data G1 to G4 from the
ADC 510, and convert the digital data G1 to G4 into touch pressure
information. For example, the touch pressure information may
include the magnitude of a touch pressure.
The memory 550 may store a look-up table including touch pressure
information set for each digital data.
Thus, the converting unit 520 can convert the digital data G1 to G4
into the touch pressure information with reference to the look-up
table stored in the memory 550.
FIG. 6 is a diagram showing a liquid crystal display according to
an embodiment of the present disclosure. FIGS. 7 and 8 are diagrams
showing sections of the liquid crystal display shown in FIG. 6.
Particularly, a section of the liquid crystal display 600, taken
along line B-B' of FIG. 6, is illustrated in FIG. 7, and a section
of the liquid crystal display 600, taken along line C-C' of FIG. 6,
is illustrated in FIG. 8.
Referring to FIGS. 6 to 8, the liquid crystal display 600 according
to the embodiment of the present disclosure may include a touch
sensor 100 described with reference to FIGS. 1 to 5.
Specifically, the liquid crystal display 600 according to the
embodiment of the present disclosure may include driving electrodes
110', sensing electrodes 120', piezoelectric materials 210', a
first substrate 610, a second substrate 620, a black matrix 650,
and column spacers 710.
The liquid crystal display 600 according to the embodiment of the
present disclosure may further include a touch controller 150
described above.
However, the configuration and operation of the touch controller
150 are the same as the above-described embodiment, and therefore,
their descriptions will be omitted.
The driving electrodes 110', the sensing electrodes 120', and the
piezoelectric materials 210', which are described herein, are
components respectively corresponding to the driving electrodes
110, the sensing electrodes 120, and the piezoelectric materials
210, which are described above. The driving electrodes 110', the
sensing electrodes 120', and the piezoelectric materials 210' may
be embedded in the liquid crystal display 600 between the first
substrate 610 and the second substrate 620 to operate as the touch
sensor 100.
The first substrate 610 and the second substrate 620 may be
disposed opposite to each other.
Also, a liquid crystal layer 700 may be interposed between the
first substrate 610 and the second substrate 620.
A plurality of color filter patterns 640 and the black matrix 650
may be disposed under the second substrate 620.
The color filter patterns 640 may include red color filter
patterns, green color filter patterns, and blue color filter
patterns. The black matrix 650 may be formed to surround the color
filter patterns 640. The black matrix has a matrix shape having
openings in which the color filter patters 640 are disposed.
The column spacers 710 are used to maintain a gap between the first
substrate 610 and the second substrate 620, and may be disposed
under the black matrix 650 to extend toward the first substrate
610. The black matrix and the column spacers 710 may be form on the
same layer and be formed of a same material through a same
manufacturing process.
The sensing electrodes 120' may be disposed under the black matrix
650, so that a user cannot view the sensing electrodes 120'. For
example, the sensing electrodes 120' may be formed over the column
spacers 710 and the black matrix 650 which are disposed over the
second substrate 620. The sensing electrodes 120' may be formed on
a top surface of the column spacer 710 which faces a first
substrate 610 and side surface of the column spacer 710.
The driving electrodes 110' may be disposed above the first
substrate 610. In this case, the driving electrodes 110' may be
disposed to overlap the black matrix 650, so that the user cannot
view the driving electrodes 110'.
For example, the driving electrodes 110' may be disposed on the
protective layer 740.
As described above, the driving electrodes 110' and the sensing
electrodes 120' may be arranged to intersect each other.
The piezoelectric materials 210' may be disposed between the
driving electrodes 110' and the sensing electrodes 120' at
intersection points of the driving electrodes 110' and the sensing
electrodes 120', respectively.
Thus, the driving electrodes 110', the sensing electrodes 120', and
the piezoelectric materials 210' are arranged to overlap the column
spacers 710 which exists in the liquid crystal display 600 in a
plan view, so that it is possible to detect a touch position and a
touch pressure while maintaining the gap between the substrates 610
and 620 as usual. The piezoelectric material and the column spacer
completely overlap in a plan view.
The liquid crystal display 600 according to the embodiment of the
present disclosure may further include components for displaying
images.
For example, referring to FIG. 8, pixel transistors TFT, common
electrodes 810, and pixel electrodes 870 may be additionally
disposed on the first substrate 610.
Each of the pixel transistors TFT includes a gate electrode 815
connected to a gate line (not shown), a first electrode (e.g., a
source electrode) 833, a second electrode (e.g., a drain electrode)
835, and a semiconductor layer 823 formed between the gate
electrode 815 and the first and second electrodes 833 and 835.
Here, the semiconductor layer 823 includes an active layer 823a and
an ohmic contact layer 823b.
A gate insulating layer 720 is formed over the gate electrode 815,
and the protective layer 740 is formed over the first and second
electrodes 833 and 835. The protective layer 740 includes a contact
hole 843 through which the second electrode 835 is exposed.
A pixel electrode 870 is formed on the protective layer 740. The
pixel electrode 870 is connected to the second electrode 835
through the contact hole 843.
For example, the pixel electrodes 870 may be disposed in the same
layer as the driving electrodes 110'.
The common electrodes 810 may be disposed on the first substrate
610. In FIG. 8, it is illustrated that the common electrodes 810
are disposed below the pixel electrode 870. However, the common
electrodes 810 may be disposed above the pixel electrodes 870 or
disposed in the same layer as the pixel electrodes 870.
An image display operation of the liquid crystal display 600 having
the above-described structure will be briefly described as
follows.
First, if a gate signal is applied to the gate electrode 815 of the
pixel transistor TFT provided in each pixel, the active layer 823a
is activated, and accordingly, the first electrode 833 transmits,
to the second electrode 835 spaced apart therefrom at a
predetermined distance, a data signal applied from a data line (not
shown) connected thereto, through the active layer 823a formed
thereunder.
In this case, the second electrode 835 is electrically connected to
the pixel electrode 870 through the contact hole 843, and
therefore, a voltage of the data signal is applied to the pixel
electrode 870.
Accordingly, the arrangement of liquid crystal molecules in the
liquid crystal layer 700 is adjusted corresponding to a voltage
corresponding to the difference between the voltage applied to the
pixel electrode 870 and the voltage applied to the common electrode
810, thereby displaying a predetermined image.
Example embodiments have been disclosed herein, and although
specific terms are employed, they are used and are to be
interpreted in a generic and descriptive sense only and not for
purpose of limitation. In some instances, as would be apparent to
one of ordinary skill in the art as of the filing of the present
application, features, characteristics, and/or elements described
in connection with a particular embodiment may be used singly or in
combination with features, characteristics, and/or elements
described in connection with other embodiments unless otherwise
specifically indicated. Accordingly, it will be understood by those
of skill in the art that various changes in form and details may be
made without departing from the spirit and scope of the present
disclosure as set forth in the following claims.
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